EM is short for Electro Magnetic. As soon as you go to vape, the electro-magnetic current will open the shield and provide the coil with e-liquid, only when it needs to. The pods are available in 0.6Ω and 0.9Ω resistances and can be used for both MTL (Mouth To Lung) and RDL (Restricted Direct to Lung) vaping.
